The present invention relates to localization of vertebrae and intervertebral discs in MR (Magnetic Resonance) images, and more particularly, to a method for automatic vertebrae and intervertebral disc localization in an MR sagital image slice.
Magnetic Resonance (MR) imaging is frequently used to diagnose abnormalities in the spinal intervertebral discs. Owing to the non-isotropic nature of MR spinal scans, physicians typically align the scanner plane with the disc in order to maximize the diagnostic value and to facilitate comparison with prior and future studies. Commonly, a planning scan is acquired of the whole spine, followed by a diagnostic scan aligned with selected discs of interest. The generally preferred presentation of the spine in an MR imaging study for the purpose of diagnosis is one in which the scanning plane is perpendicular to the axis of a targeted vertebrae or intervertebral disc. By having the vertebrae aligned with the scanning plane, minute peripheral features of the vertebrae can be more easily distinguished and accurate measurements can be made.
In order to create an aligned scan of the spine, an optimal disc plane must be determined. Conventionally, operators manually determined the optimal plane. However, manual determination of the optimal disc plane is tedious and prone to operator variation. Accordingly, automatic methods for aligning the scans of the spinal column based on the orientation of each intervertebral disc have been proposed. Standard methods for determining the orientation of an intervertebral disc require segmentation of the disc from the image. Segmentation methods such as “region growing” in turn require a seed point as an initial step. However, inconsistent results can be achieved depending upon the initial seed location.
It is desirable to determine a consistent location of the vertebral bodies (vertebrae and intervertebral discs), in order to achieve consistent alignment results.